Multi-stage transmissions of this type are preferably used with automatic transmissions of motor vehicles, wherein the effective power flow within the planetary gear sets in the respective gear step is defined by a targeted actuation of the shift elements. Here, in the case of an automatic transmission, the planetary gear sets are typically additionally connected to a start-up element, such as, for example, a hydrodynamic torque converter or a fluid coupling, that is subject to a slip effect and is provided optionally with a lock-up clutch.
The document, DE 10 2008 000 428 A1, discloses a multi-stage transmission of planetary design in which four planetary gear sets, and a total of eight rotatable shafts, one of which represents a drive shaft and another represents an output shaft of the multi-stage transmission, are disposed in a housing. Furthermore, there are at least six shift elements in the region of the shafts, and by the targeted actuation thereof, the power flow within the four planetary gear sets varies and thus, different transmission ratios can be represented between the drive shaft and the output shaft. By this means, a total of nine forward gears and one reverse gear can be engaged.